In architectural applications and building construction there are frame structures for doorways, windows or other openings formed by frame members which must be assembled at right angles. Precise angles are required whereby the mating edges provide a hairline joint having a permanent neat and trim appearance. Many of the fastening devices currently being used at the junction of the members are generally inadequate to provide proper alignment or positive engagement with one another.
One example of such a fastening device is described in U.S. Pat. No. 3,552,085, which includes a corner clip which works in cooperation with jamb anchors to establish a frame miter. For example the use of a triangular piece at the intersection of right angle frame pieces allows the ends of the pieces to move along the angled surface of the insert piece, so that there is no fixed orientation of a mitered joint as is required in most frame assemblies prior to installation. This is particularly problematic in that it requires extra time, care and skill during installation by the workmen in achieving the common right angle joint for proper fit appearance when complete.